The present invention relates to a grinder/polisher. More particularly, the present invention relates to an improved grinder/polisher for preparing samples for examination.
Grinder/polishers are in use in many industries. They are often used to prepare samples of metals, polymers, ceramics or the like for further examination, such as by microscopic examination.
Known grinder/polishers include a sample or specimen holder that is configured to rotate relative to a platen that is also configured to rotate. In this manner, there are two rotating motions occurring simultaneously. A slurry, generally abrasive, is injected onto the platen to provide an abrasive medium for grinding and polishing the specimen.
The specimen holder is supported for rotation in a chuck. The holder is a flat plate with multiple openings in which the specimens reside. In one mode, the specimens are locked into the holder and a downward force by the holder applies a pressure on the platen. As the holder and platen rotate, the pressure applied by the holder (and specimen), along with the abrasive action of the slurry, results in a grinding and polishing action on the specimen.
In another mode, the specimen floats within the holder and a plunger is moved into contact with the specimen to apply pressure to the specimen. Again, as the holder and platen rotate, the pressure applied by the plunger, along with the abrasive action of the slurry results in a grinding and polishing action on the specimen.
Movement of the holder toward and away from the platen is controlled by a drive located in the grinder/polisher head. The drive motor is used to position the holder and thus the specimen relative to the platen. One drawback to known grinder/polishers is that there is no positive positioning control or mechanism to precisely control the position of the holder relative to the platen.
The platen is supported within a bowl. The bowl serves as a repository for debris that is generated during the grinding/polishing operation. Water or another fluid is used to rinse with bowl to clear the debris. It has been found that even with known rinsing systems, debris can collect in the bowl and cause unsightly and inconvenient accumulation in the bowl. It has also been found that if a grind is particularly aggressive, the platen can heat up which, it is believed, can adversely effect specimen preparation.
Accordingly, there is a need for an improved grinder/polisher. Desirably, such a grinder/polisher includes an improved illumination system to enhance the visibility of the working area. More desirably, such a grinder/polisher has an improved rinsing/bowl clearing system. More desirably still, such a grinder/polisher has an improved system for positioning the head and specimen holder and for holding the specimens in position relative to the rotating platen.